Civil Defense Director Jorge Melendez said a yellow alert had been issued and investigators had been sent to the area to look for signs of fresh lava, but that none has been detected so far.

"We have implemented emergency measures to evacuate villages located within 3 kilometers of the volcano," Melendez said. Shelters have been set up for the evacuees, but Melendez said some inhabitants had been loath to leave their homes. "One has to leave for one's own safety," he said.

Assistant Health Minister Eduardo Espinoza said two people had been treated at hospitals for respiratory problems apparently linked to the eruption, "but we do not have any serious cases to report."

"We are providing assistance to people evacuating, and we are asking them to protect themselves against the gases, which can affect the respiratory tract," Espinoza said. He also urged those near the volcano to avoid drinking from local water sources.